To enable data communication from a source end-station or network to a destination end-station or network, packet-based networks break-up data streams into smaller packets of data. As these packets traverse a network, some of these packets can be lost due to congestion or other network limitations. This loss can have a tremendous impact on the applications leveraging the communication channel between the source and destination end-stations. Ideally, a network, from the point of view of many applications, must provide perfect performance with deterministic packet latency and no packet loss. However, the capital and operational cost to achieve perfect network performance is not practical for most service and enterprise network providers.
Accordingly, systems and methods are required which can be used with low cost networks to provide applications with a high network performance. One approach is to create new encoding protocol stacks which are installed at the end-stations to improve the response to loss and latency. However, this approach is non-trivial since all end-stations in the source and destination networks must be upgraded to use the new encoding protocol stacks.
Another approach uses network devices that intercept standard protocols, and an encoding protocol between the intercepting network devices, to recover from network loss. These devices are deployed in areas of the network where resident applications require better network performance than what is generally available in the network itself. Such devices are described in pending U.S. application Ser. No. 12/718,650, filed Mar. 5, 2010, which is a continuation-in-part of U.S. application Ser. No. 12/193,345, filed Aug. 18, 2008, which is a continuation-in-part of U.S. application Ser. No. 10/912,200, filed Aug. 6, 2004, now U.S. Pat. No. 7,742,501.
The encoding protocol is intended to reduce loss. To achieve this goal, the encoding protocol increases the overall bandwidth required within the network. The increase in bandwidth can actually result in increasing loss instead due to network constraints. The intercepting network device needs to detect this issue and react to ensure that the communicating end-stations achieve the desired application performance.
Existing access networks generally provide poor and unreliable quality. In general, the resulting performance is unreliable and quality is unpredictable. On the other hand, the backbone networks have been upgraded with high speed links and generally have sufficient capacity and the engineering is more reliable.
To avoid having to stay on the poor quality network to reach content, caching has been implemented pervasively. Caching is a solution to improve the performance by duplicating data at multiple locations such that the data is closer to the application, alleviating some of the network quality issues due to long hops.
However, not all content can be cached (e.g. real-time applications, user-generated content) and cost of caching may be prohibitive. Lastly the location of cache might still be too far away from the source therefore still resulting in poor performance.
There is a need to improve the performance of applications that cannot be cached or where caching is unaffordable or proximity is not achievable.